Back squaring attachment for lathes



Oct. 11,1927. I ,7 3 v N. KING ET AL BACK SQUARING ATTACHMENT FOR- LATHES Filed June 50. 1924 6 Sheets-Sheet 1 JJCwZAAJ/ZZZ.

- 1,644,733- N. KING ET AL BACK SQUARING ATTACHMENT FOR LATHES Filed JuneSO. 1924 6 Sheets-Sheet '2 Oct. 11,1927.

Oct. -11. 1927.

N. KING ET AL BACK SQUARING ATTACHMENT FOR LATHES 6 Sheets-Sheet 3 A "ad/7g @mv'vu I v Filed June C50. 1924 v- Oct. 11,1921. 4,733

N. KING ET AL BACK. SQUARING '"ATTACHMENT FOR LATHES -F'iled June 50, 1924 6 Sheets-Sheet 4 Patented Oct. 11, 1927.

tJhll'lEQ STATES retires ore-res.

NATHANIEL KING AND RICHARD A. ASHTON, 0F F TGIFLBURQ MASSACHUSETTS, AS-

SIG'NORS TO SENECA FALLS MACHINE COMPANY, OF FITCHBURG, MASSACHUSETTS.

BACK SQUARING ATTACEMENT FOB LATHES.

Application filed June 30, 1824. Serial No. 723,105.

This invention relates to engine lathes and is used particularly for turning and squaring-up work at several different points in its length. These operations are desirably performed at the back side of the machine at the same time that other turning operations are being performed at the front side of the machine.

It is the general ob iect of our invention to improve the construction heretofore used for such purposes, particularly by providing for more convenient operation of the mechanism.

lVith these general objects in view, important features of our invention relate to the provision of a tool supporting slide, in combination with improved mechanism for automatically advancing and thereafter retracting the tool slide relative to the work; to the provision of means for moving the tool slide at high or low speed as required and for automatically varying the speed; to the provision of mechanism for simultaneously actuating two opposed tool slides; to provision for easily and accurately adjusting the tool slide both radially and axially relative to the work; and to the provision of means for both yieldingly and positively withdrawing the tools, after the turning and squaring operations have been performed.

Our invention further relates to arrangements and combinations of parts which will be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention and a modification thereof are shown in the drawinns in which Fig. 1 is a plan view of the tool slide and support, together with a part of the driving mechanism therefor;

Fig. 2 is a side elevation of the tool slide and support, taken along the line 22 in Fin. 1;

Fig. 3 is a rear elevation of the tool slide and support;

Fig. 4: is a sectional elevation of the means for adiusting the cam roll on the tool slide;

Fig. 5 is a detail sectional elevation. taken along the line 5-5 in Fig. 2;

Fig. 6 is a sectional side elevation of the handle for moving the tool slide axially, taken along the line 66 in Fig. 5;

Fig. 7 is an end elevation of the driving mechanism. taken along the line 77 in Fig. 1 and looking in the direction of the arrow 7 in Fig. 9;

Fig. 8 is an enlarged end elevation of certain parts shown in Fig. 7 but in a diiferentrelation;

Fig. 9 is a rear elevation of the driving mechanism, looking in the direction of the arrow, 9 in Fig. 7; I

10 is an enlarged end elevation of certain parts shown in Fig. 7, looking in the direction of the arrow 10 in Fig. 9;

Fig. 11 is a detail rear elevation, looking in the direction of the arrow 11 in'Fig; 10;

Fig. 3.2 is an enlarged sectional plan view, taken along the line l2-'12 in Fig. 7';

Fig. 13 is a partial elevation of certains parts, taken substantially along the line 13-13 in Fig. 12;

Fig. 14- is an enlarged elevation of certain parts shown in Fig. 13;

i5 is a partial enlarged rear elevation, looking in the direction of the arrow 15 in Fig. 13;

16 ring;

1'? is an end elevation of a modified construction in which front and rear tool slides are operated;

18 is a plan view of the parts in 17 and 19 is a detail front elevation, looking in the direction of the arrow 19 in Fig. 17.

Referring to Fig. 1, we have shown the work d rotatably mounted upon a head or live center 20 and a tail center 21, these centers being mounted in head and tail stocks not shown and forming no part of our present invention. A portion of the bed which support-s the head and tail stocks is shown, however, at 22 and is provided with guideways, as shown in Fig. 2, upon which a base support 23 may be clamped by binding screws 24 in any selected position along the guide-way. I

A base 25 (Fig. 2) is mounted to slide transversely upon a guide-way 26 formed on the upper surface of the base support 23. A threaded stud 27 (Fig. 5) is rotatably mounted in a bearing in a block 28 firmly secured to the side of the base 25. A flange is a partial elevation of a ratchet shown 29 on the stud 27 prevents outward axial" 32 (Fig. 5). The inner end of the stud 27 is split or slotted as indicated at 33 and the stud is provided with an axial recess tapered at its inner end to receive a rod 34 having a tapered head 35. The outer end of the rod is threaded in the stud 27 and has a screw driver slot by which the tapered rod may be turned to draw it into'the stud 27 to adjust the fit of the threaded stud in the base support 23. A nut 36 is threaded on the stud 27 and holds the washer 32 in frictional contact with the handle 31. I

A rod 37 is mounted to slide longitudinally in the handle 31 and is pointed at its lower end to enter between the teeth of the pinion30. At its upper end the rod 37 has a head 38 and is surrounded by a spring 89 which normally forces the rod upward out of engagement with the teeth of the pinion 30'. The handle 31 is provided with sliding hand piece or grip 40 which may be pushed downward to cause the rod 37 to engage the teeth of the pinion.

When it is desired to adjust the base 25 longitudinally of the work on the base support 23, the stud 27 is turned by the handle 31 to produce the desired adjustment. I have thus provided a simple and convenient ratchet feed for adjustment of the base on its support, axially of the work. A tool slide 41 (Figs. 1 and 2) is mountec in guideways on the base 25 and is prefera bly provided with a raised portion 42 2) having one or more T slots or openings F 43 to receive bolts 44 by which a suitable tool block or base 45 may be secured in position. This tool block 45 is preferably provided with ribs or projections 46 fitting the T slots and aligning the tool block 45 with the tool slide 41. The tool block 45 may be slotted at different angles to receive the tools T, as indicated in Fig. 1 and the tool block may also have a threaded flange or lug 47 to receive adjusting screws 48 by which the tools T may be separately adjusted toward the work. I Binding screws 49 (Fig. 1) hold the different tools T in adjusted position.

A cam 50 2) mountedon a cam shaft 51 engages a cam roll 52 (Figs. 2 and 4) to force the tool slide 41 toward the work W. The cam roll 52 is rotatably mounted in the end of a plunger or roll carrier (Fig. 4) which is slidable in an opening 54 in the tool slide 41. The plunger 53 is slotted or grooved at 56 to receive the reduced end of a stud or screw 57 by which it is held from rotation.

A threaded stud 58 is mounted in a bearing in the front end of the tool slide 41 and is held from axial movement therein by a flange 59 at the inside of the bearing and by a Washer 60 and nut 61 on the outer end of the stud. The stud 58 is threaded into the plunger or roll carrier 53 and the roll may thus be conveniently adjusted relatively to the tool slide 41. By this adjustment, the extreme forward position of the tool T which will be reached during the rotation of the cam 50 may be varied as desired.

The cam shaft 51 is rotatable in bearings 63 (Fig. 1) at the rear end of the base 25 and is intermittently rotated by driving mechanism to be described. A chain 64 is secured at one end to the tool slide 41 and passes rearward over the cam shaft 51, from which point it hangs freely and supports a heavy weight 65 by which the tool slide 41 is drawn. rearward and the cam roll 52 is caused to firmly engage the cam 50. r

The tool slide is thus yieldingly returned to rearward position after being forced forward by the cam 50. There is a possibility, however, that the tool slide may bind or encounter unusual resistance to its return movement, and accordingly I have provided means for positively withdrawing the tool slide from cutting position. For this purpose, I provide a pin or stud 66 (Fig. 2) mounted in the side of the cam 50 and positioned to engage a hook 67 which is pivoted at 68 on an upward projection 69 of the tool slide 41 and which extends beyond the pivot 68 for engagement by a stop screw70. As the cam 50 rotates in the direction of the arrow a in Fig. 2, the stud 66 engages the hook 67 the cam roll 52 passes the point of the cam 50 and such engagement draws the tool slide 41 positively rearward. As the rearward movement is continued. the pin or stud 66 moves downward and is gradually withdrawn from the hook 67, which is limited in its downward movement by the adjusting screw or stop 70., Provision is thus made for positively withdrawing the tool slide after actuation by the cam 50.

In Figs. 17 18 and 19, I have shown a double support 71 having a tool slide 72 at the rear of the work and a second tool slide,

73 in front of the work. The slide 72 is provided with a roll 74 engaged by a cam 75 on a cam shaft 76 as previously described. The front slide 73 is mounted in transverse guide-ways 77 Fig. 19) and is connectedby a depending block 78 and a rod 79 to a link 80 which is pivoted at its rear end to a cam lever 81. The lever 81 is pivoted at its lower end to a downward and rearward projection 82 of the base support 71 and has a cam roll 83 at itsupper end engaging a second cam 84 on the cam shaft 76. A chain 85 connects the slide 72 to the usual. weight (not shown) for withdrawing the slide from the work. A heavy spring 86 (Fig. 17) may be provided for removing the front slide. 73 forward away from the work.

Driving mechanism.

Vi e will now describe the mechanism'by which the cam shaft 51 may be rotated at different speeds and may be started when desired and automatically stopped at the com pletion of a single revolution. A sprocket chain .90 (Fig. 7) is driven from the lathe spindle or from some other continuously rotating shaft (not shown) and drives a sprocket 91 mounted on a short horizontal shaft 92 (Fig. 9) which is rotatable in bearings in a casing 93, pivoted to swing about the axis of a counter shaft 94 mounted in a bracket 95 fixed to the frame of the lathe. A pinion 96 (Fig. 9) on the sprocket shaft 92 engages a gear 97 on the counter shaft 94. A fixed stud 98 7) extends through a slotted projection 99 (Fig. 9) on the casing 93 and is provided with lock nutsv 100 and 101 by which the casing 93 may be'swung forward or rearward to adjust the tension of the sprocket chain 90.

A bevel gear 102 on the counter shaft 94 engages a second bevel gear 103 (Figs. 7 and 8) on a Worm shaft 104 mounted in hearings in a bracket or support 105. The shaft 104 has a worm 106 adapted to engage a worm wheel 107 which is freely rotatable upon a shaft 108 (Fig. 12) aligned with the cam shaft 51 and connected thereto by a driving clutch or coupling 109 so constructed as to permit slight relative movements between the shafts 108 and 51. The worm gear 107 forms part of a slow speed drive for the cam shaft 51.

The high speed drive is taken from a vertical shaft 110 (Fig. 7) which is continuously rotated from any suitable drive shaft in the head of the lathe. 111 at the upper end of the shaft 110 engages a bevel pinion 112 on a worm shaft 113. The shaft 113 is mounted in suitable? fixed bearings and has a worm 114 meshing with a worm wheel 115 (Fig. 12). The worm wheel 115 is mounted on a short shaft 116 rotatable in a fixed bearing 117 and having a spur gear 118 at its opposite end, meshing with a similar gear 119 which is freely slidable and rotatable upon a sleev or bushing 120 on the shaft 108.

A clutch disc 121 (Fig. 12) is secured to the face of the gear 119'and a corresponding clutch disc 122 is secured to the adjacent face of a ratchet hub 123 on which is mounted a ratchet ring 124 (Figsf13 and 16). A pawl 125 (Fig. 14) is mounted in a recessed projection on the side of the worm wheel 107 and is retained therein by a plate 127 (Fig. 15). A spring 128 forces the pawl 125 yieldingly into engagement with the teeth of the ratchet ring 1.24 but permits the pawl to be forced outward away from the teeth as will be hereinafter described.

The ratchet hub 123 is keyed to the shaft 108 and the ratchet and shaft are normally rotated at relatively slow speed by the worm gear 107, acting through the pawl 125. The

A bevel gear 1 spur gear119, as previously described, is slidable along the shaft 108 and is freely rotatable thereon, An annular groove 130 in the hub of the gear 119 receives rolls 131 on the arms of a yoke132 (Fig. 10) mounted on a fixed pivot 133 and having a depend ing arm 134. A clutch controlling plate 135 (Figs. 10 and 11) is fixed to a projection 136 on the side of the arm 134 and projects into the path of cam plates or dogs 137 (Figs. 10 and 12) which are bolted to the periphery of the ratchet hub 123.

When the plate 135 is engaged by a cam or dog 137 on the ratchet hub 123, the yoke 132 is swung outward against the pressure of a spring 138 (Fig. 12) and separates the clutch discs 121 and 122. lVhen the dogs or cam plates 137 pass from engagement with the plate 135, the spring 138 causes the clutch discs 121 and 122 to engage each other and thereby drive the ratchet hub 123 at a relatively high speed, causing the hub 123 to run ahead of the worm wheel 107. This action is made possible by the pawl and ratchet connection between the ratchet hub and worm wheel. The shaft 108 and the connected cam shaft 51 will thus be rotated at relatively high speed, so long as the clutch discs 121 and 122 are engaged.

Stopping mechanism.

We will now describev the mechanism through which the rotation of the cam shaft is stopped after one revolution and through stud 144 (Fig. 10) on the periphery of the ratchet hub 123. -When the trip 144 engages the arm 143, the latch141 will be swung outwardly. releasing the lug 140 and allowing the casing 105 to drop and disengage the worm 106 from the worm wheel. 107; The continuous low speed drive of the cam shaft will thus be interrupted after a single revolution of the shaft.

For-releasing the latch manually, we pro vide a stopping lever 150 (Fig. 7) pivoted at 151. and actuatinga stop rod 152. A. collar 153 on the rod 152 is positioned to engage a pin 154 (Fig. 8) on the latch arm 143. The handle 150 may thus be used to depress the latch arm and release the latch 141. A spring 155 yieldingly moves the latch towards engaging position. The weight of the handle 150 holds the rod 152 in normally raised position and theup'ward movement of the rod 152 is limited by check nuts 156 (Fig. 8) on the lower end of the rod.

In order to stop the cam shaft 51 manually, it is also essential that the high speed drive shall be simultaneously disconnected and for this purpose a cam block 160 (Figs. 10 and 11) is fixed to the upper side of the worm shaft casing 105, as by a screw 161, 'and is adapted to engage the beveled lower end 162 of the yoke arm 134:. As the casing 105 is released by the latch 1 11 and drops downward to inoperative position, the cam block 160 engages the end 162 of the yoke arm and moves the same from the dotted line to the full line position shown in Fig. 11, thus separating the clutch discs 121 and 122 and disconnecting the high speed drive. A stop 165 (Fig. 8) limits downward movement of the casing 105,

Having thus fully described our invention and the construction thereof, it is believed that the general operation of the machine will be easily apparent. The hand lever'150 is used both for starting the machine and also for manually stopping the machine if desired. In starting the machine. the lever 150 is depressed, causing the check nuts 156 to act against the worm casing 105, swinging the same upward so that the worm wheel will be engaged. The casing is secured in raised position by the latch 14-1. The worm wheel 107 thereafter makes one revolution, during a portion of which the high speed drive is released from the plates or dogs 13'? and advances the lathe tool toward operative position or withdraws the same rapidly from such. position. During the turning operation, the high speed drive is disconnected by the plates or dogs 187 and the cam shaft is driven at the desired slow speed. At the completion of one revolution, the trip 144 releases the latch 141 and the cam shaft 151 comes to rest until again started by the operator. In the construction shown in Figs. 17 18 and 19, the cam shafts operate two tool slides or carriages simultaneously in opposite directions.

Having thus described our invention and the advantages thereof, we do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but what we claim is 1. In a lathe, a back squaring attachment comprising a base, a tool slide mounted for movement transversely of the lathe on said base. an actuating cam for said slide, means to yieldingly withdraw said slide. means to positively withdraw said slide, s id positive withdrawing" means becoming positively engaged if the normal yielding withdrawal of said slide is retarded. and means to automatically disengage said positive withdrawing means as said slide reaches a predetermined withdrawn position...

2. In a lathe. a back squaring attachment comprising a base, a tool slide mounted for movement transversely of the lathe on said base, an actuating cam for said slide, means to yieldingly withdraw said slide, a stud on said cam and a hook on said slide engaged by said. stud to positively withdraw said" slide. I

3. In a. lathe, a back squaring attachment comprising a base support, a base, a tool slide mounted on said base, and means to adjust said base on said support, said means comprising a stud having a bearing in said base and threaded in said support, a pinion fixed to said stud, a handle pivoted on said pinion, a plunger in said handle, and a handle grip depressible to engage said plunger with said pinion, whereby said pinion may be moved angularly.

1. In a lathe, a tool slide movable transversely of said lathe toward and from the axis of the work, an actuating shaft connected to move said slide transversely, means to turn said shaft successively slowly and rapidly during a single revolution thereof, and means to stop said shaft after said single revolution is completed and while the work driving mechanism of the lathe continues in operation. V

5. In a lathe, in combination, a tool slide, mechanism to move said slide transversely of said lathe toward and from. the axis of the work, a. high speed drive for said mechanism, a low speed drive for said mechanism, automatic meansto shift said mechanism from one drive to the other at predetermined points in the operation of the lathe, and means to stop said mechanism after a single reciprocation of sad slide and while the work driving mechanism of the lathe continues in operation.

6. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft conifected to move said slide toward and from the axis of the work, a relatively slow speed drive for turning said shaft, a relatively high speed drive for turning said shaft, and manual means to disconnect both said high and said low speed drives and to stop the shaft at any desired point while the work driving mechanism of the shaft continues in operation.

..7. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to reciprocate said slide toward and from the axis of the work, means to turn said shaft successively slowly and rapidly during a single revolution thereof,manual means to start said shaft in rotation and automatic means to stop said shaft at the end of a single reciprocation of said slide and while the work driving mechanism of the lathe continues in operation.

8. In a lathe, a tool slide movable trans versely of said lathe, an actuating shaft connected to move said slide, meansto turn said shaft both slowly and rapidly during "a single revolution, manual means to start said shaft in rotation and to stop the movement of said shaft at any desired point while the work driving mechanism of the lathe continues in operation, and automatic means to stop said shaft at the end of a single revolution.

9. Ina lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to move said slide, a slow moving worm wheel loose on said shaft, a hub fixed to said shaft, a pawl and ratchet connection between said worm wheel and said hub, a second driving member loose on said shaft and rotated at relatively high speed, and a clutch connection between said driving memher and said fixed hub, said hub over-running said slow running worm wheel when connected to said high speed driving member.

10. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to move said slide, a hub fixed to said shaft, a relatively slow speed driving memher in continuous driving relation to said hub, a relatively high speed driving member normall free from said hub and automatic means to connect said high speed member to said hub during certain predetermined parts of a revolution of said shaft, thereby causing said hub to over-run its driving engagement with said slow speed driving member.

11. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to move said slide, a relatively slow speed worm wheel to drive said shaft, a relatively high speed worm wheel to drive said shaft, a continuously rotated worm and worm shaft for each worm wheel, a pivoted bearing casing for the slow speed worm shaft, a clutch connection between said high speed worm wheel and said actuating shaft, and means to release said casing to disengage said slow speed worm and to simultaneously disengage said clutch in the high speed drive. 1

12. In a lathe, a tool slidemovable transversely of said lathe, an actuating shaft connected to move said slide, a relatively vslow speed wormiwheel to drive said shaft, a relatively high speed worm wheel to drive said shaft, a continuously rotated worm and Worm shaft for each worm wheel, a pivoted bearing casing for the slow speed worm shaft, a clutch connection between said high speed worm wheel and said actuatingshaft, a latch for said casing, means to release said latch and thereby disengage said slow speed worm, and a cam on said casing effective to simultaneously disengage said clutch connection. v

13. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to move said slide, a relatively slow speed worm wheel to drive said shaft, a relatively high speed Worm wheel to drive said shaft, a continuously rotated worm and worm shaft for each worm wheel, a pivoted bearing casing for the slow speed worm shaft, a clutch connection between said high speed worm wheel and said actuating shaft,

a latch for said casing, automaticand man ual means to release said latch, and automatic means to disengage said clutch connection. I

14. In a lathe, a tool slide movable transversely of said lathe, an actuating shaft connected to move said slide, a relatively slow speed worm wheel to drive said shaft, a relatively high speed worm wheel to drive said shaft, a continuously rotated worm and worm shaft for each worm wheel, a pivoted bearing casing for the slow speed worm shaft, a clutch connection between said high speed worm wheel and said actuating shaft, a manually operated handle connected for movement in one direction to raise and latch said casing and in the opposite direction to unlatch and release said casing, and means operated by said casing to release said clutch connection.

In testimony whereof we have hereunto 

